Phonograph needle



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esley w E KIDD ETAL PHONOGRAPH NEEDLE F led Oct s 1947 Oct. 21, 1952Patented Oct. 21, i952 fl'HO NOGRAPH NEEDLE Wesley E. Kidd and Robert L.Metz'enberg, cm-

cago, Ill., assignors to Sears; Roebuck and 00., Chicago, 111., acorporation of New York Application Qctober 6, 1947, Serial No. 778,102

It is well known that in the audible reproduc-.

tion of sound recordings through the medium f a tone arm pickup device,incidental noise characteristics in the sound groove as wellas otherextraneous sound disturbances are sometimes superimposed onto therecorded sound transmission frequencies. Among such are vibrationalresonance efiects usually accompanying high frequency notes as well asscratch noises usually audible with lower notes or soft notecombinations. The overall result of such disturbances is to distractfrom the pure tonal qualities of music and to impart harsh mechanicalsound characteristics, as a result of which musical reproductions orrecordings are often too manifestly distinguishable from original musicor voice.

Various devices have been tried to overcome these and other mechanicalor foreign sound characteristics which accompany .the reproduc tion ofsubject matterrecorded and such have included a wide range orapplication incident to the electrical and mechanical features of soundreproducing apparatus. The present invention concerns itself withimprovements toward inhibiting the transmission of mechanicalreproduction noises through the medium of damping them out at theinitial sensing element, the sound track coursing needle.

Towards this end there is proposed herewith an. improved type ofphonograph needle characterized .by the provision of a graduated taperthroughout its shank portioncoupled .jwith a significant angular offsetor displacement near the lower region of the shank and having locatedwithin the displace portion or neck of the needle a series of paralleldisc damping vanes equally spaced one from the other and of identicalcircular pattern. The location of these discs has been determinedexperimentally in relation to the other structural characteristics ofthe needle whereby their efiect is to damp out recording scratches,vibrational overtones, and secondary tonal effects and to materiallyeliminate or reduce these effects until they are inaudible to humanperception. The way in which this phenomenon is believed to be ac- 2Claims. (01. 274-48) complis-hed through the medium of theaforementioned damping discs is an effect in the nature of counteringthe vibrational sound disturbances by reflecting against the side of thevanes cancelling out frequencies of similar wave characteristics.

For a more comprehensive understanding of the present inventionreference will now be had to the accompanying drawing and to thefollowing detailed specification in which like reference charactersdesignate corresponding parts throughout and in which: a

Fig. l is a side elevation of a portion of a horizontal turntablemounted for vertical axis rotation having a tone arm pickup whichcarries a needle designed according to the present invention,

Fig. 2 is an enlarged side elevational view of the needle featured inFig. 1 showing the pickup head in dotted phantom, Fig. 3 is an enlargedtransverse sectional view taken approximately on line 3-3 of Fig. 2, andFig. is a furtherenlarged transverse sectional view through the jewelpoint needle socket extremity indicating the needle surface curvatureand its manner of securement.

Attention is now directed more specifically to Fig. 1 wherein thereference numeral H designates a base within which there may be housedany of various types of turntable rotating'mechanism. Through this basethere protrudes a vertical spindle l2 which may beof considerablelength, as in the case of well known types of multiple record playingapparatus, or of shorter length in the case of single operationapparatus. Carried by the spindle l2, usually in splined close fittingalignment, is a turntable collar 13 integrally associated with theturntable disc 14, the surface [5 of which is covered by a felted fabricso as to insure against marring or scratching of the record disc itplaced thereon for sound reproduction. r

The turntable rotates in a clockwise direction as viewed in plan so thatthe flange I! will be passing from right to left as viewed in Fig. l,the spiral cutting in the surface of the recording disc I6 isaccordingly an involute approaching the center during clockwise trackingof its course.

The pickup arm I8 is customarily supported on a horizontal pivot,weighted and balanced preferably so as to bear with its needle end at aslight preponderance of weight ranging from one and one-half to sixounces by reason of which the extremity of the needle 2| is made tofollow in the sound groove of the disc IS. The element within which theanchor shank 22 of the needle 2| is carried is preferably one which ispossessed of sound transmitting characteristics between its point ofengagement with the needle shank 22 and its point of communication withan amplifier device either mechanical or electrical. I

The needle receptacle or anchoring media is customarily provided with atightening screw 23 to integrate the two elements in a soundtransmission sense. The angle of inclination of the shank 22 asmanifested in Figs. 2 and4 is 'the conventional angle and is the same asthat of the jewel carrying socket extremity 24. mediate the shankportion 22 and socket 24 is a special type of damping beam 25 formed asan integral portion with the shank 2| and neck 24 and constitutedprincipally of a continuation of th taper which begins at approximatelythe point 26 of the shank and which continuesat a very gradual rate ofslope to the extremity of the needle. Thedamping beam 25 merges with theshank 2| at an angle of curvature approximately similar to that at whichthe same beam merges with the point extremity 24 but near the center,longitudinally speaking, of the beam 25 there are formed three identicalspaced disc flanges indicated 26, 21, and 28. The adjacent sides of thediscs 26 through 28 are preferably parallel or as nearly so asmanufacturing methods will permit, so that certain sound frequenciesstriking the sides of the discs will rebound at the same frequencycancelling out the initial eii'ectsand resulting in a muting or scratchsound inhibiting characteristic.

These flanges are equally spaced one from the other as best shown inFig.2, The edges of said discs are preferably flattened as at 29. Thesedamping vanes 26 to 28 not only serve the functional purpose of dampingvibration and casual noises from being transmitted ;at an audibleamplitude through the shank .of the needle 2| but also as an alignmentof identical height protruding engagement elements these flanges afforda means whereby the needle may be more effectively grasped, held, andplaced for critical adlustment in the tone arm needle socket.

In conjunction with the aforedescribed damping implementation, it hasbeen found expedient and economically advantageous to provide this typeof needle with a permanent jewel hard extremity. Accordingly the end ofthe needle is drilled as at 3| and thereinto is placed a shaped sapphirepoint 32, retention being effected by cementation, and the point beingprofiled in correspondence with intersecting asymptotes, the effect ofwhich has been found to contribute towards a lesser Wearing of the sidesurfaces of recording grooves consistent with a more faithful responseto the sound characteristics.

While the present invention has been explained Inter 4 and describedwith reference to a specific embodiment, it is to be understoodnevertheless that numerous modifications and variations may beincorporated without departing from the essential spirit or scopethereof. It is accordingly not intended that the breadth of theinvention be construed in terms of the specific disclosure of theaccompanying drawings'fnor by the words of the foregoing detaileddescription; but instead to be accorded a latitude of interpretation asindicated by the hereunto appended claims.

The invention claimed is:

l. A phonograph needle comprising, a principal shaft taperingprogressively smaller from a securement shank portion diameter to asensing but in different planes, an intermediate portion Number of saidshaft having substantially identical angularity with said shank portionand with said point portion, and a series of substantially paralleldamping vanes integral with and perpendicular to the axial center ofsaid intermediate portion. 2. An oiiset type phonograph needle whichcomprises, a shank shaped as-a tapering cylindrical metal rod bent intothree portions of which a first or securing portion is of largestdiameter, a second or vane-supporting portion is of progressivelydiminishing diameter ranging from the diameter -ofsaid first portion,and of which a third is of further progressively smaller di ameterranging from that of said second portion, said first and thirdportionsbeing substantially parallel to each other, and said second portionforming an angle with respect to said first-and third portions, "and aplurality of-similar damping vanes secured to said second portion havingflat sides parallel to each other and spaced from one another wherebythere is produced a sound damping effect limited to scratch noise levelsof sound frequency.

E. Kinn, ROBERT L. METZENBERG.

REFERENCES CITED The following references are of record in the file ofthis patent: i

UNITED. STATES PA'I'ENT'S liame Date 1,039,208 ,Steinert Sept. 24,19121,084,573 Claussen Jan. 13, 1914 2328. 8 Capps Sept. "7, 1 4 2,342,813Mason s Feb. z9,, 944 2,495,934 Kondrath Jan. 31, 1950,

FOREIGN PATENTS Number Country Date 8,562 Great Britain Apr. 8, 1999202,493 Great Britain Aug. 23, 1923 350,887

Great Britain June 18. 1931

